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Radish (Rhaphanus sativus) is a fast-growing vegetable crop that belongs to the Brassicaceae family. Native to the eastern Mediterranean area, this seed-grown crop is well suited to Sunset's Climate Zones H1, H2, A1 to A3 and zones 1 to 45. With its juicy, crisp texture and sweet or spicy flavor, this cool-season root vegetable is a favorite in salads. It can easily grow in a window box. Depending on the variety, radishes can be started in spring, late fall or early winter for a harvest about 22 to 70 days later.

1

Spread a 1-inch layer of coarse gravel over the bottom of a 1 to 5-gallon window box to help promote drainage. Add moist potting mix to the window box up to 3/4 inch from the top. Tamp down the soil so it's firm in the container.

2

Sprinkle the radish seeds about 1/2 inch apart over the soil and cover them with a 1/2-inch layer of potting mix. Level the soil surface with your hand and moisten it with a water-filled spray bottle. Stretch plastic wrap over the window box to insulate the seeds and promote soil moisture retention. Keep the soil consistently moist by spraying it with water throughout the germination period.

3

Place the window box in a warm area. Aim for a temperature between 55 to 85 degrees Fahrenheit and expect germination within four to 11 days. After germination, remove the plastic wrap and place the seedlings outside on a partial shady to sunny outdoor windowsill, for two to four hours. Gradually increase the duration that you leave the seedlings outside for and permanently leave them on the windowsill after about one week.

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4

Thin winter variety radish seedlings to 2 to 4 inches and thin spring varieties to 1 inch. Remove the weak, small seedlings by cutting them with scissors at soil level.

5

Feed the radishes an all-purpose, water-soluble fertilizer according to packaging instructions.

6

Water the radishes as needed so the soil remains moist -- not soggy -- at all times. Avoid overwatering the radishes, because this may trigger leaf growth instead of root growth.

Things Needed

1 to 5 gallon window box

Coarse gravel

Potting mix

Spray bottle

Plastic wrap

Scissors

All-purpose fertilizer

Tips

Avoid harvesting radishes too late, because they may develop a very pungent taste and a spongy texture.

Photo Credits

Eising/Photodisc/Getty Images

About the Author

Kimberly Caines is a well traveled model, writer and licensed physical fitness trainer who was first published in 1997. Her work has appeared in the Dutch newspaper "De Overschiese Krant" and on various websites. Caines holds a degree in journalism from Mercurius College in Holland and is writing her first novel.